Your correspondent released a scrolling shoot ‘em up for the Spectrum last week to some… response but, since that particular genre is more commonly the territory of a certain other 8-bit system, it only seemed proper that a version be produced for it as well. So in keeping with the “grand tradition” set down by games publishers during the early 1980s of merely sticking the number 64 on the end of a game’s name we now have Stercore 64, a close to exact port of the Spectrum original which only changes things for the C64’s palette and adds some SID-powered music that burbles away to itself in the background during play.
There are graphical variations to allow for the different palettes, but the way that the scrolling background and all of the moving objects are handled during play is the same on both computers, using software-generated sprites rather than the significantly easier to program hardware ones that the C64 has available. All of the object rendering code for both versions of Stercore were written by your correspondent – it’s always been commonplace for Spectrum developers to write their own code for these tasks – and the only significant difference between versions is the layout of the screen memory which, to your correspondent’s mind at least, is actually less convoluted on the C64.
Regardless of what the author has claimed previously, it really doesn’t require a “mathematical genius” to write a game like Stercore for either platform and it’s worth noting as well dear reader that your correspondent deliberately avoided using the C64’s hardware sprites and scrolling which usually make developing 2D action-oriented games easier. Although it would have to sacrifice some of the colour, a “re-imagined” version of the game could have offered far more detail in the background graphics and larger moving objects whilst still retaining all of the speed.
 Game developer Bob Pape has previously written about his early steps on the Spectrum and trying to draw objects by directly calling the BASIC PLOT command before realising how much faster it would be to write his own routines. The game he’s most famous for is R-Type, considered to be one of the best scrolling shoot ’em ups on the Spectrum.